An integrated circuit at the 28 nanometer node or beyond, containing core metal oxide semiconductor (MOS) transistors which operate at a core voltage, for example 1 to 1.5 volts, and input/output (I/O) MOS transistors which operate at a higher I/O voltage, for example, 1.8 to 2.5 volts, is fabricated using photolithography process with a 193 nanometer light source. Forming the core transistors and the I/O transistors while maintaining a fabrication cost and complexity of the integrated circuit at or below a desired level is problematic.